What hardware do you have?
I have seen this type of behavior ( where nothing is displayed by HCI utilizes )myself and don’t know why.
How much time and what happened between hcitool’s No such device
and 2017-11-08 19:05:02.567336 ?
What bluetooth devices do you have ?
bdaddr E9:A4:EF:14:A2:72 (Random)
ruvvi tag heard from 2 times during this 8 second dump
bdaddr 73:79:9D:59:BE:CE (Random)
bdaddr 98:D6:BB:1F:86:0E (Public)
bdaddr 5F:20:2D:57:D7:EA (Random)
Cambridge Silicon Radio
CSR8510 A10 USB Bluetooth Dongle
Sorry I couldn’t be more help.